1. Field of the Invention
This invention relates to wireless communication systems and methods for performing a handover, and more particularly, to a communication system and method for performing a handover to a femto base station.
2. Description of the Related Art
The term ‘femto-’ is a prefix in the metric system denoting a factor of 10−15. A femto cell refers to a device that can improve the coverage of cellular systems in relatively small areas. This femto cell is controlled by a base station, which is called a femto base station. A femto base station refers to an indoor base station that is very small, consumes little electric power, and is intended to be used in a home/office. The term femto cell is frequently used to refer to a pico-cell. However, the femto cell is also more advanced in terms of functions than the pico-cell. A femto base station, serving as a small cellular base station connected to a broadband router, connects conventional 2G and 3G networks to a backbone network of mobile communication, via a DSL link, etc., in order to transmit voice signals and data.
In Release 8 of the 3GPP Long Term Evolution (LTE), evolved Node B (eNB) and home eNB, which are base stations, have been defined. The eNB is a macro base station that operates general macro cells. The home ENB is a femto base station that operates femto cells.
When user equipment intends to perform a handover from a macro-base station to a femto base station, it must be registered in the femto base station. That is, in order to perform a handover from a macro-base station to a femto base station by user equipment, Access Control is required to ascertain whether the user of the user equipment is permitted to use services from the femto base station.